Selective drive assembly



Nov. 24, 1959 J. T. HELLYER 2,913,930

SELECTIVE DRIVE ASSEMBLY Filed NOV. 50, 1956 r l I hi... I

W v m gg/ U ted States Pate SELECTIVE DRIVE ASSEMBLY John T. Hellyer, Wayne, 11]., assignor to Cribben and Se rton Company, Chicago, 11]., a corporation of Illinois This invention relates to a selective driveassembly, and more particularly to a selective drive clutch assembly wherein a plurality of driven members .all operatively connected .with a drive member are selectively coupled thereto for selective'or independent operation. Theinvention hasutility-in any environmental setting wherein this result is desired and, for example,is useful inconnection with dish washer apparatus.

There are'numerous applications wherein it is desired to selectively drive one or more of a plurality of members by means of a single 'drive member, such as a motor, which remains coupled or connected to all of the driven members at all times. An example of an apparatus in which this result is desired is an automatic dish washer adapted for home use. Home dish washersmost generally employ a pump which is used in pumping water from the bottom of the tank or container to a point above the level of such tank for delivery to -a suitable drain. In the past, several home dish washer models havelgravity drains, but drains of this character are becoming outmoded and certain of the plumbing laboratories specifications now require that drain water be pumped upwardly to the top. level of the tank and then discharged into a drain. Therefore, theuse of a pump is becoming an essential, and of course a motor for driving the same isalso airequisite.

Dish washers also customarily employ an impeller or other turbulator for creating a turbulence in the. water within the dish washertank since turbulence increases the cleansing action of the liquid therein. "'An example of a dish washer employing an impeller may be found by reference to Patent No.,2,657,095. The impeller disclosed, in this'patent is supportedfor rotation and, as it rotates, it provides a wall of water extending upwardly through acentral plane in the tank, and that *wall of water is caused to walk from front to rear of the tank. This specific impeller is frequently referred to in the art as a sweep flow. It will be apparent that some power means, such as an electric motor, is necessary to rotate the impeller. 1

An object of this invention is to provide apparatus employing a selective driveassembly, wherein a single drive member (such as an 'electricmotor) is operative to selectively drive aplurality of members such as a pump and an impeller in a domestic dish washer. Another object of the invention is in the provision of apparatus of this general character, and wherein the single drive motor is constantly coupled to the driven members, both during periods when it is driving the same and periods wherein there isno' driving relation between the drive motor and one or more of the driven'members.

Still another object is in the provision ofdish washer orlike apparatus having adrive member and a plurality of driven members, and in which each of the driven members is equipped with a clutch, and wherein the drive member is selectively operable in opposite directionsthe drive member being ,connected to all .of the driven members, and the clutches being so arranged that when the motor is rotating in one direction, certain of the driven members are clutched thereto while other of the driven members are uncoupled by their clutches, and vice versa. provide in apparatus of the character described, a first driven member equipped with a one-Way clutch, a second driven member equipped with a one-way clutch, and a selectively reversible drive member connected with the driven members through the one-way clutchesthe clutches being oppositely oriented so that when one is drivingly coupling the drive member to its driven member, the other clutch is disconnecting the drive member from its driven member, and vice versa.

Still a further object is to provide apparatus of the character described, in which the drive member (or more specifically, a reversible motor) is equipped with a friction clutch which is drivingly connected to the driven members, the friction clutch being of a centrifugal type and operable irrespective of the direction of rotation of the motor, and. being effective in its operation to gradually couple the driven member thereto as the motor picks up speed, whereby a maximum load is not placed on the motor until it has picked up full speed, and whereby the motor cannot be stalled outin the event that one of the driven members becomes locked. Additional objects and advantages 'will become apparent as the specification develops.

. Anlembodiment of the invention isillustrated in the accompanying drawing, in which Figure l is a front view in elevation of dish washer apparatus embodying the invention, and in which one of the front panels is removed to show with more clarity the selective drive assembly of the apparatus; Figure 2 is a vertical sectional view taken along the line 22 of Figure 1; Figure 3 is anend view in elevation of the motor clutch with portions broken away to show one of the centrifugal friction members in section; Figure 4 is a vertical sectional view of the motor clutch taken along the line 44 of Figure 3; Figure 5 is a vertical sectional view taken along the line 5-5 of Figure 2 to show .one of the one-way clutches; and Figure 6 is a sectional view similar to that of Figure 5, but showing the other of, the one-way clutches. Reference will first be made to Figure l which illustrates a domestic dish washer designated generally with the numeral 10; and since Figure l is a front view thereof, the dish washer 10 is seen to have a panel 11 that provides a door or closure for gaining access to the interior of the tank or container which. is illustrated in part in Figure 2 and is designated with the numeral 12. The closure door 11 has a handle 13 to facilitate the opening and closing thereof. The dish washer apparatus is supported on a bottom perimetric frame 14 which has vertical. frame members 15 and 16 extending upwardly therefrom. The precise details of the dish washer construction may vary considerably, and the portions of the dish washer thus far described have no particular application to the invention; and since they may be varied substantially without affecting the same, no further description thereof will be set forth.

Figure 2 illustrates most clearly that the bottom wall 17 of the tank 12 at the forward end thereof is turned downwardly to provide a flange 19 that is faced by the front wall 20 of the tank. Thus, a type of reinforcing is provided for the tank, and in both Figures 1 and 2 this reinforced area is designated by the numeral 21. The tank may be cradled or otherwise supported by the frame of the dish washer apparatus, and centrally has a depending portion, or portion lower than the rest, and connected with the interior of the tank at this area is an opening communicating with a fitting 22. One side of the fitting 22 is connected by conduit 23 to a pressure Patented Nov. 24, 1959,

A further object of the invention is to switch 24 that, through suitable switching, controls the flow of water into the tank and regulates the elevation of the Water therein. This fitting 22 is also connected through a conduit 25 to a pump structure that is designated generally with the numeral 26. The conduit 25 leads into the inlet side of the pump, and the outlet or discharge thereof is connected with a drain conduit 27 adapted to be connected to a suitable discharge.

Figure 1 shows that the dish washer may be equipped with a thermostat 28 suitably connected with a heater for controlling the temperature of the Water within the tank 12. This same figure also illustrates that a dish washer is provided with a motor 29 carried by a bracket 30 welded or otherwise rigidly secured to the frame. The specific dish washer herein illustrated is also provided with an impeller or turbulator structure designated generally with the numeral 31, and it may take the form of the sweep flow structure illustrated and described in the patent identified by number hereinbefore.

The motor 29 is a reversible motor, but other than that may be of any suitable type, and it has been found that a one-third horsepower reversible motor is of sufli' cient capacity to function properly in this apparatus. Because of the clutching arrangement that will be described hereinafter, an inexpensive reversible motor may be used, and in such motors a slight delay (perhaps in the nature of about 30 seconds) is inherent in shifting the rotation of the motor from one direction to another. However, in this setting or use, a delay of such duration is unnoticed and is certainly tolerable.

As shown most clearly in Figures 3 and 4, the motor 29 has a shaft 32 having at the outer end thereof a driven element 33 aifixed thereto so that relative rotation therebetween is prevented. The element 33 may be pressed onto the shaft 32 or otherwise secured thereto. The outer end of the driver element 33 is cylindrical, and provides a bearing support upon which anti-friction bearings 34 are mounted; and bearings 34 rotatably receive and support thereon a sheave or pulley wheel 35 that is prevented from moving outwardly along the shaft 32 and cylindrical end of the element 33 by a thrust bearing 36, also mounted upon the element 33 and which is held in place thereon by a retainer ring 37. The sheave 35 cannot move inwardly along the element 33 because of the abutment thereof with a shoulder 38 provided by that member. It is apparent from Figure 4 that the pulley wheel or sheave 35 is formed integrally with a laterally extending, annular flange 39 that defines a drum or driven clutch element.

The driver element 33 and driven clutch element 39 are adapted to be frictionally coupled in drive relation by a pair of centrifugally actuated friction elements or shoes 40 and 41 that are diametrically opposed within the drum 39. The centrifugally actuated elements 40 and 41 each comprise a rigid metal shoe 42 having an arcuate outer edge that conforms to the curvature of the drum 39, and'which has secured thereto by adhesives or other suitable means a friction band 43. As is seen most clearly in Figure 3, each of the shoes 42 has a flat, straight inner side that is slotted longitudinally (as shown at 43a), and centrally the longitudinally extendng slot 43a communicates with a central bore 44 extend-. mg transversely thereof. The shoes 42 ride or are carrled by a rigid plate 45 affixed to the driver element 33 at a point approximately midway between the drum 39. The plate 45 has cut-away portions corresponding to the flat sides of the shoes and are slidably received w thin the slots 43a thereof. The plate is also provided with a pair of diametrically extending guide fingers 46 WhlCh are alignable with and are received within the bores 44 in the shoes.

The slots 43a of the shoes and the cutaway portions of the rigid plate 45 are so dimensioned that when the motor shaft 32 is at rest, the friction elements 40 and 41 are free of the hub or drum 39. Thus, he l otor shaft 32 can rotate Without rotating the pulley wheel 35, and vice versa. However, when the motor shaft 32 begins to rotate and picks up speed, the driver element 33 affixed thereto begins to rotate at an ever increaslng velocity, as does the rigid plate 45 afiixed thereon. The fingers 46 of the plate in their engagement with the walls of the bores 44 rotatably drive the centrifugal friction elements 40 and 41, and as their speed increases, centrifugal force causes the same to move outwardly from the rotational axis of the shaft 32.

As the force urging the friction band 43 into engagement with the drum 39 increases, the frictional grip between the friction band and the drum increases, and the drum of course begins to rotate. Since the pulley wheel 35 is integral with the drum, it rotates and will of course rotate any pulley belt entrained thereabout. Ultimately, the shaft 32 and the drum 39 will rotate at the same speed. However, as the motor 32 picks up speed and a load is present on the drum 39 providing an inertia resisting rotation thereof, slippage is permitted between the friction bands 43 and drum so that the motor driving the shaft 32 is not excessively loaded. Thus, the motor load progressively increases as it picks up speed, and as a result it is possible to avoid terrific instantaneous overloads and high current drain when the motor 29 is initially turned on. It will be appreciated that the drive assembly disclosed in Figures 3 and 4 and which has been described is effective irrespective of the direction of rotation of the shaft 32 and, therefore, this friction clutch assembly accommodates a reversible motor.

Referring now back to Figure 1, it is seen that the pulley wheel 35 has a belt 47 entrained thereabout, and that belt is also entrained about a sheave or pulley wheel 48 which is fixed on a cylindrical end projection of a cam 49 equipped with a cam end 50. The cam 49 is rotatable with respect to a drive shaft 51 being supported thereon by bearings 52. The shaft 51 is a drive member for the pump 26, and in the specific illutration that shaft is supported for rotation in a plurality of support bearings 53, 55 and 56, and at its inner end carries an impeller 57 which may be anchored thereto by a nut 58. The pump and the impeller 57 thereof functions in a conventional manner, and draws fluid in through an inlet 59 and expells the same through an outlet opening provided therefor in the casing or scroll 60.

Since the pulley wheel 48 is rotatably supported with respect to the shaft 51, means must be provided for coupling it thereto in order to effectuate a driving relation therebetween. Such engagement is etfectuated through a one-Way clutch assembly that is designated generally with the numeral 61, and comprises in addition to the cam 49 and end portion 50 thereof, a hub or driven clutch element 62 which is affixed to the drive shaft 51 by a pin 63. The hub 62 has a rearwardly extending annular surface that encloses the cam end 50 and, as is seen most clearly in Figure 5, a pair of balls 64 and 65 are interposed between portions of the cam element 50 and the hub 62.

The functioning of the clutch assembly 61 is best understood by referring to Figure 5 wherein it is seen that the cam 49 has a pair of oppositely oriented recessed portions defined between lobes 66 and 67. The recesses are defined in part by cam surfaces 68 and 69 that are inclined or progress outwardly from the rotational axis of the cam and toward the hub 62. With this arrangement, it will be apparent that rotation of the cam in one directionspecifically, in a counter-clockwise direction as viewed in Figure 5will cause the balls 64 and 65 to be rigidly locked between the outermost portions of the cam surfaces and the hub, whereby the hub will be rotatably driven. On the other hand, when the cam member rotates in the opposite direction (clockwise), the balls 64 and 65 ride freely at the deep ends of the cam surfaces, and there is no driving engagement effective between the cam and the hub.

Referring again to Figure 1,it is seen that the pulley belt47 is entrained about the sheave or pulley wheel 70, and through a clutch arrangement designated generally by the numeral 71 (shown in Figure 6) drives the impeller shaft 72 of the impeller or turbulator within the tank 12 of the dish washer. The clutch arrangement 71 is identical with the clutch 61 heretofore described except that the corresponding .cam surfaces. are oppositely oriented so that when the clutch 61 is driving the pump shaft 51, the clutch 71 is riding freely, and vice versa. Therefore, a detailed description of the clutch 71 as to the structural parts thereof will not be set out,and because of the correspondence of parts to those of the clutch 61, the same numbers will be employed to indicate the parts thereof, except that the letter a will be added thereto.-

Preferably, an automatic take-up is provided for the pulley belt 47 so as to maintain the appropriate tension therein. Such an arrangement is illustrated in Figures 1 and 2 in connection with the pump 26. Referring first to Figure 2, it is there seen that the housing 60 of the pump is provided with a pair of ears or bosses 73 and 74 along the upper side thereof, and these ears which are spaced apart are provided with parallel bores therethrough having, respectively, bearings 75 and 76 mounted therein that slidably receive shafts 77 and 78.

The shafts also extend through openings in depending walls 79 and 80 provided by a bracket 81 having a base 82 welded or otherwise rigidly secured to the bottom wall 17 of the tank 12. Thus, the pump assembly is supported by the tank and is free to move horizontally with respect thereto since it is slidably carried on the shafts 77 and 78. These shafts in turn are constrained against movement within the bracket 81 by clamp collars or other comparable means. Referring toFigure 1, it will be apparent that coil springs 83 are interposed between the depending legs 79 of the bracket and the ears of the pump casing and surround the shafts 77 and 78 so as to bias the pump assembly toward the left (as seen in Figure 1) or in a direction tensioning the pulley belt 47.

It is believed that the operation and functioning of the apparatus described will be apparent from the foregoing description thereof, but for purposes of providinga ready summary, a brief review will now be set forth. It may be mentioned, although it is not particularly essential to the functioning of the invention herein considered, that domestic dish washers ordinarily have but one control switch which when actuated initiates a cycle of operation that is carried to completion automatically through a plurality of stages, certain of which cause the motor 29 to rotate in one direction, and other of which causes it to reverse itself in carrying out different functions.

In any event, when the motor 29 is energized so that the shaft 32 thereof rotates in either direction, the centrifugal friction elements 40 and 41 of the friction drive clutch are thrown outwardly by centrifugal force, and as they frictionally engage the hub 39, that hub is caused to rotate with the shaft. Assume that initially the motor 29 is energized to rotate the shaft 32 thereof in a counter-clockwise direction (as viewed in Figure 1), the sheave 70 will then be rotated in the same counter-clockwise direction, and as will be apparent from a detailed view of the impeller one-way clutch 71 as shown in Figure 6, the clutch will simply slip or ride freely with the result that thereis no driving connection between the sheave 70 and impeller shaft 72. Onthe other hand, counter-clockwise rotation of the pulley wheel 48 of the pump assembly will cause the cam 50 to rotate in a counter-clockwis direction, as viewed in Figure 5, and the clutch assembly 61 will drivingly couple the pump shaft 51 to the pulley wheel, causing the pump to be energized.

Precisely the reverse situation occurs when the motor 29 is energized so as to have rotation of the shaft 32 the friction clutch.

thereof in a reverse direction. mam eventQthe'pump clutch 61 will ride freely while the clutch 71 will drivingly couple the pulley wheel 70 and impeller shaft 72, whereby the tank impeller will be rotated.

The arrangement described permits the use of a motor 29 which is relatively inexpensive, and one of the main reasons for this is that the motor is protected against instantaneous overloads when it is first energized. That is to say, the friction clutch arrangement permits the motor to attain its operating speed quickly, for the driving coupling between the motor and the members or members driven thereby is gradual due to the action of In addition, the arrangement perunits a single motor to be usedto perform a dual function, and this represents a substantial advance over domestic dish washer apparatus now employing more than one driven member, for such known commercial washers require the use of separate motors for the individual driven members. Thus, through the selective drive clutch assembly, one motor is made to perform the functions heretofore fulfilled by a plurality of motors.

While in the foregoing specification an embodiment of the invention has been described in considerable detail for purposes of illustration, it will be apparent to those skilled in the art that numerous changes may be made in those details without departing from the spirit and principles of the invention.

I claim:

1. In combination with a dish washer having a pair of driven members, a reversible drive member, a pair of one-way clutches, one for each of said driven members, and means connecting portions of said one-Way clutches with said drive member, said one-way clutches being mounted and oriented so as to function in opposite directions, said portions of both of said one-way clutches being operative whenever said drive member is operative but the said portion of only one of said one-way clutches being coupled to the remaining portion thereof, whereby rotation of said drive member in opposite directions selectively rotates said driven members one at a time.

2. In dish washer apparatus of the character described, a pair of driven members, a reversible motor for driving said members, a centrifugal clutch for said motor and being characterized by being operable independently of the direction of rotation of the motor, and means for selectively connecting said centrifugal clutch with said driven members so that rotation of said motor in any one direction, drives only one of said driven members.

3. The structure of claim 2 in which said last mentioned means comprises a pair of one-Way clutches, one of which is characterized by efiectuating a driving connection when rotated in one direction and the other of which effectuates such a driving connection when rotated in the opposite direction.

4. In apparatus of the character described, a first driven member equipped with a one-way clutch, a second driven member equipped with a one-way clutch, a reversible drive member, and pulley wheels and a pulley belt entrained thereabout for connecting said drive member with each of said clutches, said clutches being oppositely constructed one-Way clutches whereby rotation of said drive member in one direction drives one of said driven members but not the other and vice versa when the drive member is rotated in a reverse direction.

5. In dishwasher apparatus of the character described, a centrifugal clutch, a pair of oppositely-oriented oneway clutches, and belt means coupling portions of said clutches together and to said centrifugal clutch, said portions of both of said one-way clutches being operative whenever said centrifugal clutch is operative but the said portion of only one of said one-way clutches being coupled to the remaining portion thereof.

6. In combination with a dishwasher, a reversible motor, a pump, an impeller, a pair of one-way clutches,

one for said pump and one for said impeller, said one-way clutches being mounted for efiectuating a driving connection when rotated in opposite directions so that one drives in a clockwise direction and the other in a counterclockwise direction, and means connecting each of said clutches with said motor, the last-mentioned means comprising a plurality of pulley wheels and a pulley belt entrained thereabout.

7. In dishwasher apparatus, a reversible drive member, 'a pair of driven members, each driven member being equipped with a one-way clutch, means coupling said drive member with each of said clutches, said clutches being oriented for driving said driven members in opposite directions, said one-way clutches each including a first portion continuously driven by said coupling means and rotatable relative to its associated driven member, each of said clutches also including a second portion fixed 10 cam surfaces defined by said first and second portions.

References Cited in the file of this patent UNITED STATES PATENTS 5 2,441,926 Zahn et al. May 18, 1948 2,699,854 Trout 'Jan. 18, 1955 2,753,967 Bowers July 10, 1956 

